Gas cap



FIG. 1 left side view of gas cap in a closed position;

FIG. 2 front view of gas cap in a closed position;

FIG. 3 rear view of gas cap in a closed position;

FIG. 4 top view of gas cap in a closed position;

FIG. 5 right side view of gas cap in a closed position; and,

FIG. 6 perspective view of gas cap in an open position.

The broken line showing of elements of the bottom of the gas cap form no part of the claimed design. 

The ornamental design for a gas cap, as shown and described. 